Services and config files should stickt to either one not both. Unless
user choose not

not "care". ( services listening to IPv6 when IPv6 is not enabled? )

Which means if not enabled, all service's and configuration should be
clean of IPv6 entry's
until enabled.
So lets revert a few years of software development then.

If that actually what it takes to do make it listen to eithver IPv6 or
visa versa then yes..

The WorldWideWeb is far from switching to IPv6.
Really?

Let me refrase that the people that are running the hardware behing the
WWW are not IPv6 ready

atleast the majority of them, thou protocols and standards are ( mostly )

Institutions/company's wont spent $$$ in buying expensive IPv6 or
dual
capable IPv4/IPv6 Hardware
unless they are forced to do due so...

Or the equipment that is produced comes with IPv6 capability by
default to give the hardware folks a reason to sell more hardware.

I don't know the strategy behind this decision from the beginning?

The world is running out of IPv4 addresses and NAT is a stop-gap that
breaks things. Plus other nice things like QOS.

( maybe publicity stunt or to show the world we could )
Yeah, weee, the crowd goes wild *applause applause*
Yep, you got it. _That's_ the reason it is being implemented.
</sarcasm>
Throw the dice and see if you make the reality check..

Let's turn it of by default and reconsider it after 3 - 5 years or
later

Hell, let's just stop progress altogether. We've landed on the moon
after all. There's nothing left to do is there?

Seriously, can I ask what has prompted this or is it just a slow day
at the office?

If I choose to disable something, it should be disabled and those thing
related to it.